In vitro evaluation of the effect of hypothermia on coagulation in dogs via thromboelastography.

OBJECTIVE: To evaluate the effect of temperature alterations on in vitro coagulation in healthy dogs using thromboelastography (TEG). DESIGN: In vitro study. SETTING: University teaching hospital. ANIMALS: Six healthy purpose-bred laboratory dogs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thromboelastograph tracings were created daily for all test subjects and used to generate control values for R, K, α, and MA. Control values were compared to test samples incubated at 42, 39, 36, 33, 30, and 27°C. At temperatures ≤ 30°C, a significant increase in K values and a significant decrease in the α values were noted. There were no significant differences detected for R and MA among any of the test temperatures. CONCLUSIONS: Hypothermia results in in vitro coagulation changes in healthy dogs as determined by whole blood analysis using TEG. The data suggest that while clots may form more slowly at decreased temperatures, the ultimate strength of the clot appears unaffected.

Imaging diagnosis--acquired pectus excavatum secondary to laryngeal paralysis in a dog.

A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral laryngeal paralysis. Radiographically, there was pectus excavatum with a mediastinal shift to the right. Arytenoid lateralization was performed, relieving the upper respiratory obstruction, and the sternal deformity also resolved. Chronic upper respiratory obstruction should be considered in dogs with pectus excavatum. Furthermore, correction of upper respiratory obstruction has the potential to result in resolution of pectus excavatum.

Evaluation of dexmedetomidine and ketamine in combination with various opioids as injectable anesthetic combinations for castration in cats.

OBJECTIVE: To compare the efficacy and cardiorespiratory effects of dexmedetomidine-ketamine in combination with butorphanol, hydromorphone, or buprenorphine with or without reversal by atipamezole in cats undergoing castration. DESIGN: Prospective, randomized, split-plot, blinded study. ANIMALS: 30 healthy male cats. PROCEDURES: Cats were assigned to receive dexmedetomidine (25 ?g/kg [11.4 ?g/lb]) and ketamine (3 mg/kg [1.4 mg/lb]) with butorphanol (0.2 mg/kg [0.09 mg/lb]; DKBut; n = 10), hydromorphone (0.05 mg/kg [0.023 mg/lb]; DKH; 10), or buprenorphine (30 ?g/kg [13.6 ?g/lb]; DKBup; 10). Drugs were administered as a single IM injection. Supplemental isoflurane was administered to cats if the level of anesthesia was inadequate for surgery. At the conclusion of surgery, half the cats (5 cats in each treatment group) received atipamezole (250 ?g/kg [113.6 ?g/lb], IM) and the remainder received saline (0.9% NaCl) solution IM. All cats received meloxicam (0.2 mg/kg, SC) immediately prior to the conclusion of surgery. RESULTS: All drug combinations induced lateral recumbency, and intubation was achievable in 13 of 30 (43%) cats at 10 minutes after injection. Supplemental isoflurane was needed for the surgery in 1 of 10 of the DKBut-, 2 of 10 of the DKH-, and 7 of 10 of the DKBup-treated cats. Cats that received atipamezole had a significantly shorter recovery time. CONCLUSIONS AND CLINICAL RELEVANCE: DKBut and DKH combinations were suitable injectable anesthetic protocols for castration in cats commencing at 10 minutes after injection, but cats receiving DKBup may require additional time or anesthetics for adequate anesthesia.

Evaluation of dexmedetomidine and ketamine in combination with opioids as injectable anesthesia for castration in dogs.

OBJECTIVE: To compare efficacy and cardiorespiratory effects of dexmedetomidine and ketamine in combination with butorphanol, hydromorphone, or buprenorphine (with or without reversal by atipamezole) in dogs undergoing castration. DESIGN: Prospective, randomized, split-plot, blinded study. ANIMALS: 30 healthy client-owned sexually intact male dogs. PROCEDURES: Dogs (n = 10 dogs/group) were assigned to receive dexmedetomidine (15 µg/kg [6.82 µg/lb]) and ketamine (3 mg/kg [1.36 mg/lb]) with butorphanol (0.2 mg/kg [0.09 mg/lb]; DKBut), the same dosages of dexmedetomidine and ketamine with hydromorphone (0.05 mg/kg [0.023 mg/lb]; DKH), or the same dosages of dexmedetomidine and ketamine with buprenorphine (40 µg/kg [18.18 µg/lb]; DKBup). All drugs were administered as a single IM injection for induction and maintenance of anesthesia for castration. At conclusion of the surgery, 5 dogs in each treatment group received atipamezole (150 µg/kg [68.18 µg/lb], IM), and the remainder received saline (0.9% NaCl) solution IM. Cardiorespiratory variables and quality of anesthesia were assessed. Supplemental isoflurane was administered to the dogs when anesthesia was considered inadequate during surgery. RESULTS: All drug combinations rapidly induced anesthesia. Dogs were intubated within 10 minutes after injection. Supplemental isoflurane was needed during surgery in 1, 3, and 4 dogs in the DKBup, DKBut, and DKH groups, respectively. Dogs that received atipamezole had a significantly shorter recovery time. Some dogs in each group had bradycardia and hypoxemia with hypertension. CONCLUSIONS AND CLINICAL RELEVANCE: DKBup was the most suitable injectable anesthetic combination used. Recovery was shortened by IM administration of atipamezole. There were minimal adverse effects in all groups.

Effects of anesthetic protocol on normal canine brain uptake of 18F-FDG assessed by PET/CT.

The purpose of this study was to assess the effects of four anesthetic protocols on normal canine brain uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) using positron emission tomography/computed tomography (PET/CT). Five clinically normal beagle dogs were anesthetized with (1) propofol/isoflurane, (2) medetomidine/pentobarbital, (3) xylazine/ketamine, and (4) medetomidine/tiletamine-zolazepam in a randomized cross-over design. The standard uptake value (SUV) of FDG was obtained in the frontal, parietal, temporal and occipital lobes, cerebellum, brainstem and whole brain, and compared within and between anesthetic protocols using the Friedman test with significance set at P < 0.05. Significant differences in SUVs were observed in various part of the brain associated with each anesthetic protocol. The SUV for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs. Dogs receiving medetomidine/tiletamine-zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group. We concluded that each anesthetic protocol exerted a different regional brain glucose uptake pattern. As a result, when comparing brain glucose uptake using PET/CT, one should consider the effects of anesthetic protocols on different regions of the glucose uptake in the dog's brain.

Gallbladder agenesis in a Maltese dog.

This report describes the diagnostic evaluation of a 7-month-old, female Maltese dog with elevated liver enzymes. Marked elevations of alanine transferase were the significant clinical findings. A diagnosis of gallbladder agenesis was made, based on lack of a gallbladder on ultrasonography and on surgical exploration. Gallbladder agenesis is a rare condition described in humans but not previously reported in dogs.

Buried tension sutures: force-tension comparisons of pulley, double butterfly, mattress, and simple interrupted suture patterns.

OBJECTIVES: To compare suture patterns (simple interrupted, modified pulley, horizontal mattress, double butterfly) by use of a novel in vitro model that quantifies force required for closure against tension. STUDY DESIGN: In vitro study. SAMPLE POPULATION: Suture constructs. METHODS: An in vitro suturing frame was constructed with extension springs to provide a standard resistance against movement of 2 panels of loops toward each other. Four different suture patterns were applied to the frame in randomized trials. The frame was affixed to a tensiometer that measured the force required for each suture pattern to close a fixed distance (3.81 cm) at a constant rate (5.08 cm/min) against the tension (0.6 kg/cm) of the extension springs. The closure distance and tension were selected subjectively to mimic tension encountered clinically during wound reconstruction oncologic surgical procedures. RESULTS: The modified pulley suture required the least force to close, followed by the double butterfly, simple interrupted, and horizontal mattress patterns. CONCLUSIONS: The modified pulley suture and double butterfly suture patterns require less force to close a given distance under tension than either simple interrupted or horizontal mattress suture patterns. CLINICAL RELEVANCE: Application of tension relieving suture techniques for fascia, subcutaneous, and buried-knot subdermal suturing should be considered to facilitate direct closure of wounds under tension. Modified pulley and double butterfly suture patterns offer some mechanical advantage by requiring less force to achieve closure compared with other suture patterns that might be used in reconstructive surgery.

Laparoscopic ovariohysterectomy in nine dogs.

Minimally invasive surgery has been found in humans to reduce pain, incidence of infections, and duration of hospitalization. Minimally invasive procedures are also being described in veterinary medicine. Laparoscopic ovariohysterectomy (OHE) was performed on nine, healthy, intact female dogs using a Harmonic scalpel. Creatine kinase values were determined both before and 12 hours following the laparoscopic OHE; the magnitude of the difference between preoperative and postoperative creatine kinase values did not correlate with length of operative time, length of incisions, or amount of hemorrhage. Complications included one dog that had an omental herniation that was primarily repaired and one dog with seroma formation. Median surgical time for all dogs was 60 minutes (range, 35 to 100 minutes).

Microvascular free tissue transfer of the rectus abdominis muscle in dogs.

OBJECTIVE: To assess donor-site morbidity and survival of the rectus abdominis muscle with an overlying skin graft after free tissue transfer to a medial femorotibial defect in dogs. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Phase 1: 6 canine cadavers; phase 2: 7 adult mixed-breed dogs. METHODS: Phase 1: The rectus abdominis muscle was removed from canine cadavers, muscular and vascular dimensions were recorded, and angiography was performed. Phase 2: Muscular transfer was performed through anastomosis of the caudal epigastric artery and vein to the saphenous artery and medial saphenous vein. Transferred tissues were evaluated on postoperative days 3, 6, 10, and 13. Animals were examined daily until euthanasia between postoperative days 31 and 42. Postmortem angiograms were performed and tissues collected for histopathologic evaluation. RESULTS: Phase 1: Appropriate vascular dimensions for microvascular anastomosis were confirmed and surgical technique perfected. Phase 2: Muscular excision produced minimal donor-site morbidity. All muscles survived after microvascular transfer and angiography confirmed vascular patency. All of the skin grafts survived, with one graft undergoing partial necrosis. CONCLUSIONS: The rectus abdominis muscle can be successfully transferred to a medial femorotibial defect and can serve as a bed for acute skin grafting. No significant donor-site morbidity is associated with its removal. CLINICAL RELEVANCE: Microvascular free tissue transfer of the canine rectus abdominis muscle has not been previously described. This technique provides a new alternative for repair of appropriate wounds. Additional studies are needed to define its utility in clinical patients.